No-load electromagnetic simulations of a hydropower generator considering the effect of rotor whirling

Year 2015, Volume: 3 Issue: 3, 124 - 134, 30.12.2015

Yogeshwarsing Calleecharan Jan-olov Aidanpää John R. Brauer

Abstract

Electromagnetic (EM) analysis of hydropower generators is

common practice but there is little emphasis on studying the effect of rotor

whirling in the analysis. This paper explores the effect on electromagnetic

analysis as the rotor is allowed to whirl both in forward and in

backward directions under no-load conditions. As a hydropower generator

rotor shaft can experience whirling when under eccentric operation,

the objective is to examine how whirling can affect the unbalanced

magnetic pull (UMP), flux densities, damper currents, and ohmic losses

in a synchronous hydropower generator. These results are obtained in

a commercial FEM-based EM field modelling software package that

allows various degrees of freedom in motion types and multiple motion

components to be set. It is seen that backward whirling tends to induce

higher eddy currents than forward whirling does.

Keywords

eccentricity, electromagnetic simulations, hydropower rotor, no-load, whirl

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